Welcome to the Piano World Piano ForumsOver 2.5 million posts about pianos, digital pianos, and all types of keyboard instruments
Join the World's Largest Community of Piano Lovers
(it's free)
It's Fun to Play the Piano ... Please Pass It On!

Is there a way to test original wire to help choose correct replacement wire?

I have two Chickerings on my plate. A 109-C, 1896, and a scale 19, 1867. The 109 is underway, the 19 is in the contemplation phase.

Not too long ago, we had two choices in wire. More sililar to each other than different. Mapes or Roslau. The question of proriety was minor, as there was no real choice. Today there are more options, like Paullelo. But options mean choice, and choice requires information if it is not to be a blind choice.

I have the original wire from the 109. Does anyone know of a test to determine the best match in new wire?

There was tremendous competition in the 1800's for the strongest wire.

Interestingly, the stronger the wire, the stiffer.

Regardless of wire though, resulting tension will be related to mass, string length and pitch. If you leave the wire sized unchanged, the piano will be under the same stress or tension.

The character of sound will be related to the stiffness of the wire.

Feel the wire in your hands.Test the tensile strength by loading it until it breaks. Choose a wire of similar strength.There may be a simple scientific method for measuring stiffness, I have to profess ignorance here.

"It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt."Mark Twain

Would the long term tension on 90-110 year old piano wire affect its stiffness?I would think so.Would that same factor affect its tensile strength?One would assume so, since they are more likely to break.

It seems to me, due to these factors, that any evaluation of the old wire, as a means to choose the new wire, would be difficult and likely deceptive.

I share an interest in the subject due to a small grand which I am doing soon. From what I understand, the choice of wire type will be very important to getting a clean sound. It may even be that a deliberate choice to lower tension via lower gauges with a softer wire will be part of my answer for this piano.

To use soft wire you have to stay on low BS% then it raise from note 49 60% minored BS to the top at 80%

But I know at last one major modern brand that use high BS% yet in the mediums, and I find similar data on 1915 French piano (very even progression, but very high solicitation)

That plays a role in the mechanical behavior of the wire, better flow of tone, an important parameter, but the numbers we use in Europe are computed after a lowering of 20 25% of the breakin strain limit of the wire (a security taking in account the bends and the coils)

So it is difficult to compare numbers on both sides of the pond..

Professional of the profession. Foo Foo specialistI wish to add some kind and sensitive phrase but nothing comes to mind.!

Would the long term tension on 90-110 year old piano wire affect its stiffness?I would think so.Would that same factor affect its tensile strength?One would assume so, since they are more likely to break.

It seems to me, due to these factors, that any evaluation of the old wire, as a means to choose the new wire, would be difficult and likely deceptive.

I share an interest in the subject due to a small grand which I am doing soon. From what I understand, the choice of wire type will be very important to getting a clean sound. It may even be that a deliberate choice to lower tension via lower gauges with a softer wire will be part of my answer for this piano.

Likely there is some change. I would not let that deter me from investigating how the original wire behaves.

Chickering, for a time, recorded one page per piano notes on many details, including the brand of wire they used.

You can likely get a copy of the page from the log book from the Smithsonian American History Museum in DC.

Your piano may or may not have the extended details, it is worth a call to see.

Details of how music wire was made and it's tensile strengths are well recorded in the 1800's.

The MFA in Boston has a very good Chickering collection. Darcey Kironin, Curator, would be the person to contact. He has very good resources there.

"It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt."Mark Twain

Precision is out of question, and, for instance we are not even sure of the original pitch of the instrument - pitch change the sollicitation of the wire, hence change the BS% and change the iH a little.

Professional of the profession. Foo Foo specialistI wish to add some kind and sensitive phrase but nothing comes to mind.!

#2020633 - 01/24/1307:16 PMRe: The right wire for late 19th century grands
[Re: Olek]

Regardless of wire though, resulting tension will be related to mass, string length and pitch. If you leave the wire sized unchanged, the piano will be under the same stress or tension.

Larry,thanks for responding.

We have touched on this before. Does not an increase in the strength of a wire come with an increase in the density of the wire, and a greater mass per unit of length? Would this not require an increase in tension to reach pitch?

Originality. The customer is interested in experiencing the piano the way it was when new. Chickering sold thousands of these pianos for very good money. He wants to hear what it was that kept Chickering flourishing for so many years. Perhapse that is the best possible piano, or at least the best possible 100 year old Chickering.

We did a 1881 Chickering scale 93 thirty years ago and dropped most of the gauges back .002" and added half sizes. The plate was massive, but the sound board assembly was dainty. I wondered if the piano ever could have had real down bearing. It was as if they were going on the premises that maximum string mass was the answer to all things and if you could build a plate to hold the tension, all was well.

Weird job. The first rebuilder had passed away and I took on at least three contracts to finish up. This one and, I think, two upright players.

From my notes which I have just looked over, that steel was STRONG stuff. Smallest size was 14!

Oh, yeah,Chickering was not kidding around. I'm not planning on changing the string scale. That is why I'm trying to determin the proper stiffnesss of wire to install. If the stiffness affeccts the tone, as Larry said, then I don't want to use a wire any stiffer than what is right.

The board does seem to be a bit more compliant than a Steinway. And from what I could tell from teardown measurements, Chickering employed a one to one ratio between crown and bearing in this 109. Once again, no messing around. though I would think a high compliance board could handle that type of bearing without choking.

Did you find that in yours? The 1867 scale 19 has a board that looks like a guitar bottom. Thin little triangular ribs spaced about 10 inches apart. I've never seen anything like it, and I cant wait to recrown it and hear what it sounded like.

Paulello has a typogram, available to download for free, which can help you determine what wire to use. You will have to measure the existing scale and input the data to the typogram. Here: http://stephenpaulello.com/en/typogramme

Original Chickering scales from that period were determined by tradition and reckoning, and perhaps a bit of experimentation, just like other pianos of the time. We can do better these days.

Wire changed a lot back then. There was a chart in some book I read, probably Edwin Good's, giving the breaking strengths of wire from various periods in the 1800s, and it increased quite a bit as time went on.

I'd have to say that I'm a bit skeptical about all this talk about the exact wire type being important. There are really 3 inherent parameters of the wire that are important. I say inherent, because, for the moment, I want to defer thoughts about how well the wire was manufactured.

The three parameters are density (mass per unit volume), Young's modulus (sometimes called the modulus of elasticity, or the tensile modulus), and the yield strength. The modulus of elasticity is a measure of how much force is required to stretch the material a certain amount--one could think of it as stiffness. The yield point is the amount of strain the material can take before it starts to permanently deform.

The density of all steels is so close that for our purposes we can consider them to be the same. The modulus of all steels is essentially the same. The modulus for the stronger grades of stainless steel (400 series) is about 3% less than steel.

The yield point varies not only for the particular grade of steel, but also its temper. Many people don't realize that the tempering process only affects the yield point, but not the modulus. So, basically, all wire that would be suitable for piano strings has essentially the same stiffness, and the same density--it is really only the yield point that varies. Does variation in yield strength really affect sound. Well, I'm skeptical. Remember that all piano wire is tensioned well below the yield point.

Of course, we still have to consider the quality of the wire. The best wire would be extremely consistent both within any given length and between different batches. It's physical dimensions should be accurate and repeatable. It should have a smooth, shiny surface to help inhibit rust.

Last edited by Roy123; 01/25/1309:10 AM.

#2020973 - 01/25/1309:12 AMRe: The right wire for late 19th century grands
[Re: BDB]

Original Chickering scales from that period were determined by tradition and reckoning, and perhaps a bit of experimentation, just like other pianos of the time. We can do better these days.

Well,now,let's not think of our predecessors as cavemen knapping pianos out of flint. If, as you say, there was no calculation involved in the creation of these scales, then that leaves only tonal results as a guide. And the tonal results are what was being sold. My personal quest is to hear these pianos for what they were. My fear is that through modification all the personality will be wrung out of the piano. Back in the day decisions were made and fortunes bet on them. I want to hear what they were so confident about.

Originally Posted by BDB

Wire changed a lot back then. There was a chart in some book I read, probably Edwin Good's, giving the breaking strengths of wire from various periods in the 1800s, and it increased quite a bit as time went on.

I have two Chickering scale77 9'4s in my space at the moment. One is from 1867, the other from 1897. The two are dramaticly different for all their similarities. The 67 has a bent rim, the 97 is a sectional. Both are all original, so the evolution of the wire and the scale should be apparent. Someday, when I have a free month, I plan on doing a comparative anatomy study.

The problem is that the tonal results of the stringing scale were modified by the voicing process. Poor stringing scales required more voicing, just to begin to have what they considered adequate tonal results. If you get a copy of Piano Tone Building, which is probably available from Del, you can see that this was a concern.

If you restring a few pianos, and rescale a few pianos, you begin to understand what differences rescaling makes. The results are subtile, but probably closer to what the early makers were aiming for. I have rescaled a Chickering from about 1890, and it has required very little voicing, and stays in tune very well. The main difference is an improvement in the transition from the bass to the treble, which is a problem with many old pianos.

I'd have to say that I'm a bit skeptical about all this talk about the exact wire type being important. There are really 3 inherent parameters of the wire that are important. I say inherent, because, for the moment, I want to defer thoughts about how well the wire was manufactured.

The three parameters are density (mass per unit volume), Young's modulus (sometimes called the modulus of elasticity, or the tensile modulus), and the yield strength. The modulus of elasticity is a measure of how much force is required to stretch the material a certain amount--one could think of it as stiffness. The yield point is the amount of strain the material can take before it starts to permanently deform.

The density of all steels is so close that for our purposes we can consider them to be the same. The modulus of all steels is essentially the same. The modulus for the stronger grades of stainless steel (400 series) is about 3% less than steel.

The yield point varies not only for the particular grade of steel, but also its temper. Many people don't realize that the tempering process only affects the yield point, but not the modulus. So, basically, all wire that would be suitable for piano strings has essentially the same stiffness, and the same density--it is really only the yield point that varies. Does variation in yield strength really affect sound. Well, I'm skeptical. Remember that all piano wire is tensioned well below the yield point.

Of course, we still have to consider the quality of the wire. The best wire would be extremely consistent both within any given length and between different batches. It's physical dimensions should be accurate and repeatable. It should have a smooth, shiny surface to help inhibit rust.

The yeld point have been studied, I was also sceptikal until in an exchange with the director of a very reputed German factory, he confirmed to me it was an important parameter, assuring to me they begin a 50% (lowered yeld point in that computation) then going up to 80% in the medium range (I hear you US tech having the heair dressed on head !)

Hence 80% from there up to the high treble.Since then, when I tune or listen to those pianos, I notice how the high mediums and the treble are crisp, clear and the strings react so fast to the hammer impact.

I measured the iH lowering also, with a few Hz raise in pitch even Tunelab can show you a lowering of iH.

Ther have been studies tending to prove that the more the string is near its breaking poin, the more it makes a well build spectra.

The other parameters, as you say, does not change much (mass of steel) , remains iH and BS% , which are linked.

AN old piano mounted with modern wire, the yeld point will be so low that the tone is too inharmonic and also nasal and hard.

"Soft" wire of old times was BTW way richer and warmer than the ones we have today.

PS I finally understand that the more you tense a steel wire, the more it is resilient, which by evidence is good for the tone, the more tense wire is more elastic than the less tense .. less flexible, more elastic

Last edited by Olek; 01/25/1312:31 PM.

Professional of the profession. Foo Foo specialistI wish to add some kind and sensitive phrase but nothing comes to mind.!

Percentage of breaking strength depends almost entirely on the length of the string, no matter what the gauge. Inharmonicity varies according to the gauge of the string. The percentage of breaking strength therefore has almost no effect on inharmonicity.

Percentage of breaking strength depends almost entirely on the length of the string, no matter what the gauge. Inharmonicity varies according to the gauge of the string. The percentage of breaking strength therefore has almost no effect on inharmonicity.

You are correct, however given that a scale designer might be looking for a given tension, then for a longer string, the diameter must be reduced to maintain a given tension. The net result of the longer string and smaller diameter would be less inharmonicity. I suspect this is why people think that a string tensioned to a greater % of its yield point produces a clearer tone--it's not really the % of yield strength that's the issue, it's rather the longer, thinner string.